The problem of how to remove an over-tightened cap from a screw-top jar, though it happens many, many times, can be very demanding. Most persons, when the task arises, struggle with the jar in one hand and the cap in the other hand, trying to exert a forceful twist. Often, a little moisture on the hands will cause a loss of friction, leading to the frustration that the force one's hands are capable of exerting cannot be brought to bear.
Another problem can be that the person puts so much effort into applying the unscrewing force that he loses control and, when the cap finally cracks open, the sudden loss of resistance can cause the jar to be dropped or spilled.
Often, a householder faced with a tight cap on a food jar will attempt to loosen the cap by striking blows against the cap. The potential dangers of striking the cap are all too clear.
These examples serve to illustrate that there is a need for an appliance which will simplify the task of slackening tight screw-caps, in an economical and efficient manner.
Persons with arthritis and other hand-weakening afflictions have no less a requirement to gain access to the contents of screw-top jars. The appliance is very useful to such person.
The invention arose from considerations of the problem of providing a single component, no-moving-parts low-cost appliance, made from sheet metal and requiring, in its manufacture, only such simple operations as stamping and bending, without machining.